Multi-Cell TCI Indication Across BWP Switching in 5G NR
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing transmission configuration indications (TCI) in multi-cell scheduling, particularly in 5G/NR systems, which are deployed in higher frequency bands to support increasing data traffic and diverse applications, necessitating improved radio interface efficiency and coverage.
Innovation Solution
The method involves receiving DCI formats that schedule PDSCHs across multiple cells, utilizing a BWP indicator and TCI field to determine active DL BWPs and TCI states for cells, enabling efficient transmission configuration across multiple cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a single DCI format schedules multiple cells with unified TCI states, then signaling overhead is reduced, but the complexity of determining appropriate TCI states from different activated sets increases
Solution Approach 1:
The patent segments the TCI state indication by separating scheduled cells from non-scheduled cells. The DCI format includes a TCI field that provides TCI state indications specifically for scheduled cells, while non-scheduled cells maintain their existing TCI states. This segmentation reduces the overall signaling overhead by only indicating TCI states where changes are needed, while the UE complexity is managed through clear rules for determining which cells receive TCI updates.
Solution Approach 2:
The patent applies preliminary action by pre-configuring multiple sets of activated TCI states for different BWPs before scheduling occurs. When a BWP switch is detected in the DCI format, the UE can efficiently determine which TCI states to apply based on pre-established mapping relationships between BWPs and TCI state sets, reducing real-time processing complexity.
2Reliability
If TCI states are updated for all cells in a set, then transmission configuration consistency is improved, but signaling overhead increases
Solution Approach 1:
The patent applies local quality by providing differentiated TCI state updates based on individual cell scheduling status. Only cells that are actually scheduled by the DCI format receive TCI state indications in the TCI field, while non-scheduled cells maintain their existing configurations. This localized approach ensures transmission configuration consistency is improved only where necessary, avoiding unnecessary signaling overhead for cells that don't require updates.
3Adaptability or versatility
If multiple sets of activated TCI states are maintained for different BWPs, then adaptability to BWP switching is improved, but device complexity increases
Solution Approach 1:
The patent implements universality by creating a standardized multi-set TCI state structure that serves multiple purposes: it supports BWP switching, provides TCI state indications for multi-cell scheduling, and maintains backward compatibility with single-cell scheduling. The same multi-set structure is used across different BWPs and cell configurations, reducing the need for separate management mechanisms and thereby limiting the increase in device complexity despite enhanced adaptability.
Data Source
AI summary
Methods and apparatuses for transmission configuration indication (TCI) in multi-cell scheduling. A method includes receiving first information for a set of cells and receiving a downlink control information (DCI) format that schedules physical downlink shared channels (PDSCHs) on first cells from the set. A TCI field of the DCI format provides first indicated TCI states for the first cells and second indicated TCI states for second cells that are not scheduled by the DCI format. The method further includes determining first new active downlink (DL) bandwidth part (BWPs) for the first cells based on an indicated DL BWP index in the DCI format. The first indicated TCI states are from activated TCI states on the first new active DL BWPs and the second indicated TCI states are from activated TCI states on current active DL BWPs. The method further includes receiving the PDSCHs on the first new active DL BWPs.